1 什么是操作符？
2 简单的回答可以使用表达式4 + 5等于9，在这里4和5被称为操作数，+被称为操符。 Python语言支持操作者有以下几种类型。
3 算术运算符
4 比较(即关系)运算符
5 赋值运算符
6 逻辑运算符
7 位运算符
8 会员操作符
9 标识操作符
10 让我们逐一看看所有的运算符。
11 Python算术运算符：
12 假设变量a持有10和变量b持有20，则：
13 操作符 描述符 例子
14 + 加法 - 对操作符的两侧增加值 a + b = 30
15 - 减法 - 减去从左侧操作数右侧操作数 a - b = -10
16 * 乘法 - 相乘的运算符两侧的值 a * b = 200
17 / 除 - 由右侧操作数除以左侧操作数 b / a = 2
18 % 模 - 由右侧操作数和余返回除以左侧操作数 b % a = 0
19 ** 指数- 执行对操作指数（幂）的计算 a**b = 10 的幂 20
20 // 地板除 - 操作数的除法，其中结果是将小数点后的位数被除去的商。 9//2 = 4 而 9.0//2.0 = 4.0
21 #!/usr/bin/pythona = 21b = 10c = 0c = a + bprint "Line 1 - Value of c is ", c
22
23 c = a - bprint "Line 2 - Value of c is ", c
24
25 c = a * bprint "Line 3 - Value of c is ", c
26
27 c = a / bprint "Line 4 - Value of c is ", c
28
29 c = a % bprint "Line 5 - Value of c is ", c
30
31 a = 2b = 3c = a**b
32 print "Line 6 - Value of c is ", c
33
34 a = 10b = 5c = a//b print "Line 7 - Value of c is ", c
35
36 执行程序结果
37 Line 1 - Value of c is 31
38 Line 2 - Value of c is 11
39 Line 3 - Value of c is 210
40 Line 4 - Value of c is 2
41 Line 5 - Value of c is 1
42 Line 6 - Value of c is 8
43 Line 7 - Value of c is 2
44 Python的比较操作符：
45 假设变量a持有10和变量b持有20，则：
46 运算符 描述 示例
47 == 检查，两个操作数的值是否相等，如果是则条件变为真。 (a == b) 不为 true.
48 != 检查两个操作数的值是否相等，如果值不相等，则条件变为真。 (a != b) 为 true.
49 <> 检查两个操作数的值是否相等，如果值不相等，则条件变为真。 (a <> b) 为 true。这个类似于 != 运算符
50 > 检查左操作数的值是否大于右操作数的值，如果是，则条件成立。 (a > b) 不为 true.
51 < 检查左操作数的值是否小于右操作数的值，如果是，则条件成立。 (a < b) 为 true.
52 >= 检查左操作数的值是否大于或等于右操作数的值，如果是，则条件成立。 (a >= b) 不为 true.
53 <= 检查左操作数的值是否小于或等于右操作数的值，如果是，则条件成立。 (a <= b) 为 true.
54 #!/usr/bin/pythona = 21b = 10c = 0if ( a == b ):
55 print "Line 1 - a is equal to b"else:
56 print "Line 1 - a is not equal to b"if ( a != b ):
57 print "Line 2 - a is not equal to b"else:
58 print "Line 2 - a is equal to b"if ( a <> b ):
59 print "Line 3 - a is not equal to b"else:
60 print "Line 3 - a is equal to b"if ( a < b ):
61 print "Line 4 - a is less than b" else:
62 print "Line 4 - a is not less than b"if ( a > b ):
63 print "Line 5 - a is greater than b"else:
64 print "Line 5 - a is not greater than b"a = 5;b = 20;if ( a <= b ):
65 print "Line 6 - a is either less than or equal to b"else:
66 print "Line 6 - a is neither less than nor equal to b"if ( b >= a ):
67 print "Line 7 - b is either greater than or equal to b"else:
68 print "Line 7 - b is neither greater than nor equal to b"
69 当执行上面的程序它会产生以下结果：
70
71 Line 1 - a is not equal to b
72 Line 2 - a is not equal to b
73 Line 3 - a is not equal to b
74 Line 4 - a is not less than b
75 Line 5 - a is greater than b
76 Line 6 - a is either less than or equal to b
77 Line 7 - b is either greater than or equal to b
78 Python赋值运算符：
79 假设变量持有10和变量b持有20，则：
80 运算符 描述 示例
81 = 简单的赋值运算符，赋值从右侧操作数左侧操作数 c = a + b将指定的值 a + b 到 c
82 += 加法AND赋值操作符，它增加了右操作数左操作数和结果赋给左操作数 c += a 相当于 c = c + a
83 -= 减AND赋值操作符，它减去右边的操作数从左边操作数，并将结果赋给左操作数 c -= a 相当于 c = c - a
84 *= 乘法AND赋值操作符，它乘以右边的操作数与左操作数，并将结果赋给左操作数 c *= a 相当于 c = c * a
85 /= 除法AND赋值操作符，它把左操作数与正确的操作数，并将结果赋给左操作数 c /= a 相当于= c / a
86 %= 模量AND赋值操作符，它需要使用两个操作数的模量和分配结果左操作数 c %= a is equivalent to c = c % a
87 **= 指数AND赋值运算符，执行指数（功率）计算操作符和赋值给左操作数 c **= a 相当于 c = c ** a
88 //= 地板除，并分配一个值，执行地板除对操作和赋值给左操作数 c //= a 相当于 c = c // a
89 #!/usr/bin/pythona = 21b = 10c = 0c = a + bprint "Line 1 - Value of c is ", c
90
91 c += aprint "Line 2 - Value of c is ", c
92
93 c *= aprint "Line 3 - Value of c is ", c
94
95 c /= a
96 print "Line 4 - Value of c is ", c
97
98 c = 2c %= aprint "Line 5 - Value of c is ", c
99
100 c **= aprint "Line 6 - Value of c is ", c
101
102 c //= aprint "Line 7 - Value of c is ", c
103 当执行上面的程序，它会产生以下结果：
104
105 Line 1 - Value of c is 31
106 Line 2 - Value of c is 52
107 Line 3 - Value of c is 1092
108 Line 4 - Value of c is 52
109 Line 5 - Value of c is 2
110 Line 6 - Value of c is 2097152
111 Line 7 - Value of c is 99864
112 Python位运算符：
113 位运算符作用于位和位操作执行位。假设，如果a =60;且b =13;现在以二进制格式它们将如下：
114 a = 0011 1100
115 b = 0000 1101
116 -----------------
117 a&b = 0000 1100
118 a|b = 0011 1101
119 a^b = 0011 0001
120 ~a = 1100 0011
121 Python语言支持下位运算符
122 操作符 描述 示例
123 & 二进制和复制操作了一下，结果，如果它存在于两个操作数。 (a & b) = 12 即 0000 1100
124 | 二进制或复制操作了一个比特，如果它存在一个操作数中。 (a | b) = 61 即 0011 1101
125 ^ 二进制异或运算符的副本，如果它被设置在一个操作数而不是两个比特。 (a ^ b) = 49 即 0011 0001
126 ~ 二进制的补运算符是一元的，并有“翻转”位的效果。 (~a ) = -61 即 1100 0011以2的补码形式由于带符号二进制数。
127 << 二进位向左移位运算符。左操作数的值左移由右操作数指定的位数。 a << 2 = 240 即 1111 0000
128 >> 二进位向右移位运算符。左操作数的值是由右操作数指定的位数向右移动。 a >> 2 = 15 即 0000 1111
129 #!/usr/bin/pythona = 60 # 60 = 0011 1100 b = 13 # 13 = 0000 1101 c = 0c = a & b; # 12 = 0000 1100print "Line 1 - Value of c is ", c
130
131 c = a | b; # 61 = 0011 1101 print "Line 2 - Value of c is ", c
132
133 c = a ^ b; # 49 = 0011 0001print "Line 3 - Value of c is ", c
134
135 c = ~a; # -61 = 1100 0011print "Line 4 - Value of c is ", c
136
137 c = a << 2; # 240 = 1111 0000print "Line 5 - Value of c is ", c
138
139 c = a >> 2; # 15 = 0000 1111print "Line 6 - Value of c is ", c
140 当执行上面的程序它会产生以下结果：
141
142 Line 1 - Value of c is 12
143 Line 2 - Value of c is 61
144 Line 3 - Value of c is 49
145 Line 4 - Value of c is -61
146 Line 5 - Value of c is 240
147 Line 6 - Value of c is 15
148 Python逻辑运算符：
149 Python语言支持以下逻辑运算符。假设变量a持有10和变量b持有20则：
150 运算符 描述 示例
151 and 所谓逻辑与运算符。如果两个操作数都是真的，那么则条件成立。 (a and b) 为 true.
152 or 所谓逻辑OR运算符。如果有两个操作数都是非零然后再条件变为真。 (a or b) 为 true.
153 not 所谓逻辑非运算符。用于反转操作数的逻辑状态。如果一个条件为真，则逻辑非运算符将返回false。 not(a and b) 为 false.
154 #!/usr/bin/pythona = 10b = 20c = 0if ( a and b ):
155 print "Line 1 - a and b are true"else:
156 print "Line 1 - Either a is not true or b is not true"if ( a or b ):
157 print "Line 2 - Either a is true or b is true or both are true"else:
158 print "Line 2 - Neither a is true nor b is true"a = 0if ( a and b ):
159 print "Line 3 - a and b are true"else:
160 print "Line 3 - Either a is not true or b is not true"if ( a or b ):
161 print "Line 4 - Either a is true or b is true or both are true"else:
162 print "Line 4 - Neither a is true nor b is true"if not( a and b ):
163 print "Line 5 - Either a is not true or b is not true"else:
164 print "Line 5 - a and b are true"
165 当执行上面的程序它会产生以下结果：
166
167 Line 1 - a and b are true
168 Line 2 - Either a is true or b is true or both are true
169 Line 3 - Either a is not true or b is not true
170 Line 4 - Either a is true or b is true or both are true
171 Line 5 - Either a is not true or b is not true
172 Python成员运算符：
173 除了前面讨论的运算符，Python成员运算符，在一个序列中成员资格的测试，如字符串，列表或元组。有两个成员运算符解释如下：
174 操作符 描述 示例
175 in 计算结果为true，如果它在指定找到变量的顺序，否则false。 x在y中，在这里产生一个1，如果x是序列y的成员。
176 not in 计算结果为true，如果它不找到在指定的变量顺序，否则为false。 x不在y中，这里产生结果不为1，如果x不是序列y的成员。
177 #!/usr/bin/pythona = 10b = 20list = [1, 2, 3, 4, 5 ];if ( a in list ):
178 print "Line 1 - a is available in the given list"else:
179 print "Line 1 - a is not available in the given list"if ( b not in list ):
180 print "Line 2 - b is not available in the given list"else:
181 print "Line 2 - b is available in the given list"a = 2if ( a in list ):
182 print "Line 3 - a is available in the given list"else:
183 print "Line 3 - a is not available in the given list"
184 当执行上面的程序它会产生以下结果：
185
186 Line 1 - a is not available in the given list
187 Line 2 - b is not available in the given list
188 Line 3 - a is available in the given list
189 Python标识运算符：
190 标识符比较两个对象的内存位置。两个运算符标识解释如下：
191 运算符 描述 例子
192 is 计算结果为true，如果操作符两侧的变量指向相同的对象，否则为false。 x是y，这里结果是1，如果id（x）的值为id（y）。
193 is not 计算结果为false，如果两侧的变量操作符指向相同的对象，否则为true。 x不为y，这里结果不是1，当id（x）不等于id（y）。
194 #!/usr/bin/pythona = 20b = 20if ( a is b ):
195 print "Line 1 - a and b have same identity"else:
196 print "Line 1 - a and b do not have same identity"if ( id(a) == id(b) ):
197 print "Line 2 - a and b have same identity"else:
198 print "Line 2 - a and b do not have same identity"b = 30if ( a is b ):
199 print "Line 3 - a and b have same identity"else:
200 print "Line 3 - a and b do not have same identity"if ( a is not b ):
201 print "Line 4 - a and b do not have same identity"else:
202 print "Line 4 - a and b have same identity"
203 当执行上面的程序它会产生以下结果：
204
205 Line 1 - a and b have same identity
206 Line 2 - a and b have same identity
207 Line 3 - a and b do not have same identity
208 Line 4 - a and b do not have same identity
209 Python运算符优先级
210 下表列出了所有运算符从最高优先级到最低。
211
212 运算符 描述
213 ** 幂（提高到指数）
214 ~ + - 补码，一元加号和减号（方法名的最后两个+@和 - @）
215 * / % // 乘，除，取模和地板除
216 + - 加法和减法
217 >> << 左，右按位转移
218 & 位'AND'
219 ^ | 按位异'或`'和定期`或'
220 <= < > >= 比较运算符
221 <> == != 等式运算符
222 = %= /= //= -= += *= **= 赋值运算符
223 is is not 标识运算符
224 in not in 成员运算符
225 not or and 逻辑运算符
226 #!/usr/bin/pythona = 20b = 10c = 15d = 5e = 0e = (a + b) * c / d #( 30 * 15 ) / 5print "Value of (a + b) * c / d is ", e
227
228 e = ((a + b) * c) / d # (30 * 15 ) / 5print "Value of ((a + b) * c) / d is ", e
229
230 e = (a + b) * (c / d); # (30) * (15/5)print "Value of (a + b) * (c / d) is ", e
231
232 e = a + (b * c) / d; # 20 + (150/5)print "Value of a + (b * c) / d is ", e
233 当执行上面的程序，它会产生以下结果：
234
235 Value of (a + b) * c / d is 90
236 Value of ((a + b) * c) / d is 90
237 Value of (a + b) * (c / d) is 90
238 Value of a + (b * c) / d is 50
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